The present invention relates to absorbent articles such as diapers, training pants, adult incontinence devices, sanitary napkins, feminine garments, and the like, having cuffs, including elastic leg cuffs. More particularly, the present invention relates to absorbent articles having a skin care composition disposed on the cuffs or the cuffs and the topsheet that is transferable to the wearer""s skin by normal contact and/or wearer motion and/or body heat and means for assembling such absorbent articles that are resistant to oleaginous components of the skin care composition.
The major function of absorbent articles such as disposable diapers and incontinent briefs or undergarments is to absorb and contain body exudates. Such articles are thus intended to prevent body exudates from soiling, wetting, or otherwise contaminating clothing or other articles, such as bedding, that come in contact with the wearer. The most common mode of failure for such products occurs when body exudates leak out of the gaps between the article and the wearer""s legs or waist to adjacent clothing because they are not immediately absorbed within the article and the absorbent article is not able to sustain a good fit on the wearer such that gaps are created allowing the exudates to leak out of the article.
For example, urine tends to be deposited onto the topsheet in gushes such that the urine migrates to the gaps between the article and the wearer where it can come in contact with clothing or other articles and be absorbed by these articles. Additionally, loose fecal material that is not easily absorbed by the absorbent article tends to xe2x80x9cfloatxe2x80x9d on the body-contacting surface and work its way past the gaps between the article and the legs or waist of the wearer.
Contemporary disposable diapers have a topsheet, a backsheet, an absorbent core, and one or more cuffs, typically elastic cuffs, positioned to contact the legs and/or waist of the wearer. These elastic cuffs prove effective generally to prevent wicking and overflow from the fluid laden diaper to clothing contacting the edges of the diaper in that the elastic cuffs present a barrier between the edge of the diaper and the contacting clothing, and generally in addition, provide a gasketing action about the legs or waist of the wearer to maintain a seal about the leg or waist and minimize gapping. However, because the forces generated by the elastic members are concentrated along a narrow area resulting in high localized pressures, such elastic cuffs have an increased tendency to indent and mark the skin of the wearer. These skin effects are particularly acute for products worn by infants and incontinent elderly adults due to the tenderness of their skin and its sensitivity to even slight pressures or rubbing actions.
These skin effects are even further accentuated due to the occlusion of the skin caused by such products. The occlusion of the skin by the diaper can potentially lead to skin overhydration. As a result, overhydrated skin is more susceptible to damage from abrasion due to rubbing caused by normal wearer movements and contact with the elastic cuffs. It is also generally known that overhydrated skin is more susceptible to skin disorders, including diaper rash, erythema, heat rash, abrasion, pressure marks, and skin barrier loss. The reduced barrier efficiency of abraded, overhydrated skin can further cause an increase in diaper rash. (21 CFR xc2xa7 333.503 defines diaper rash as xe2x80x9c[a]n inflammatory skin condition in the diaper area (perineum, buttocks, lower abdomen, and inner thighs) caused by one or more of the following factors: moisture, occlusion, chafing, continued contact with urine or feces or both, or mechanical or chemical irritation.xe2x80x9d).
To address the concerns of skin disorders associated with wearing diapers and other absorbent articles, the caregiver or wearer often applies skin protective and/or therapeutic products to the buttocks, genitals, anal and/or other regions before placing the absorbent article on the wearer. This procedure usually involves the caregiver applying the skin protective product to their hands, and then wiping the same on the skin of the wearer. To eliminate the need for this wasteful, messy, time-consuming, and easily forgotten procedure, there have been attempts to prepare absorbent articles which contain a skin care substance on the article""s topsheet.
The art has further responded to detrimental skin effects due to using cuffs by providing absorbent articles having cuffs with a skin care composition disposed on the cuffs to provide improved skin care benefits, particularly in skin regions in contact with the cuff during use. Such skin care compositions are transferable to the wearer""s skin to provide these skin benefits. Particularly useful skin care compositions and absorbent articles with cuffs having such skin care compositions disposed thereon are described in U.S. patent application Ser. No. 08/962,310, filed in the name of Schulte, et al, on Oct. 31, 1997 and incorporated herein by reference.
However, while such skin care compositions and absorbent articles provide substantial skin care benefits, further improvements are needed. For example it is important that the skin care composition not inhibit the functionality of the cuff in the absorbent article. Oleaginous components of the skin care composition can diffuse from the body surface of the cuff to an interior surface where such components can come into contact with the construction adhesive used to assemble the cuff. If such contact occurs, the oleaginous components can plasticize the adhesive causing a modulus reduction therein or a loss of cohesive strength. Under continuous stress this can result in creep. As used herein xe2x80x9ccreepxe2x80x9d refers to a slow yielding of the adhesive or slow release of the elastic member within the cuffs. Such creep can ultimately cause separation of the cuff material and the elastic member with a resulting loss of contractive force and increase in leakage around the cuff.
Up until the aforementioned U.S. patent application Ser. No. 08/962,310, the art had failed to recognize the value of applying a skin care composition to cuffs in an absorbent article. The art had also failed to recognize the interaction between absorbent article construction adhesives and topically applied lotions and ointments.
For instance, one of the drawbacks of applying a skin care composition to cuffs assembled with prior art adhesives such as those prior art adhesives based on block copolymer chemistry (such as styrene-isoprene-styrene hereinafter referred to as xe2x80x9cSISxe2x80x9d), was the tendency of the elastic member to creep.
U.S. Pat. No. 6,010,972 issued to Zacharias et al. on Jan. 4, 2000 discloses elastic composites assembled using an adhesive which allegedly has desirable oil resistance and processing properties. Zacharias et al. ""972, purports to teach that it is desirable that the adhesive exhibit a viscosity value less than about 40,000 centipoise at a temperature of 275xc2x0 F. Zacharias et al. ""972 further purports to teach that adhesives having viscosities higher than about 40,0000 centipoise at a temperature of 275xc2x0 F. tend to result in poor adhesive bonding to the substrate.
The drawbacks of the prior art include the need to have a viscosity low enough that the adhesive can be processed through typical process equipment and effectively applied to the substrate. The higher the viscosity of the adhesive the more difficult the adhesive is to process. Yet the viscosity can not be so low so as to prevent an effective adhesive bond from forming.
Thus, it would be very desirable to have an absorbent article comprising elastic components which maintain their integrity in the presence of oleaginous skin care compositions. It would also be very desirable to have an absorbent article which can be processed and effectively adhesively bonded at higher viscosities.
In light of this prior art it is very surprising and unexpected to find that the absorbent article of the present invention comprising a block copolymer hot melt adhesive exhibits creep resistance in the presence of lotion. Furthermore, it is surprising to find that the adhesive of the present invention can be effectively processed and applied to components of the absorbent article at higher viscosities than the prior art.
The present invention relates to an absorbent article, such as a disposable diaper, having one or more cuffs with a skin care composition disposed on (applied or migratable to) the body surface of the cuffs. In particular the invention relates to absorbent articles, particularly the cuffs thereof, that are assembled using adhesives that are resistant to oleaginous compounds used to formulate such skin care compositions.
As used herein, the term xe2x80x9ccuffxe2x80x9d includes leg cuffs including barrier cuffs, gasketing cuffs, combinations and variations thereof, transverse barriers and pockets/spacers; side panels and ear laminates; as well as waist cuffs including waist flaps, waistbands, waistcaps, and unitary waistcap/waistbands; and combinations of all or some of these cuffs.
The present invention also relates to an absorbent article to be worn by a wearer adjacent the skin, the absorbent article comprising:
a chassis comprising:
an outer covering layer comprising:
a backsheet; and
a liquid pervious topsheet joined to a backsheet; and
an absorbent core positioned between the topsheet and the backsheet;
a cuff joined to the chassis, each of the cuffs having a first surface and a second surface disposed opposite the first surface. The cuff comprises a cuff member and an elastic member wherein the elastic member has opposed elastic ends and is joined to the cuff member using an oil resistant adhesive. The adhesive exhibits an apparent viscosity less than about 20,000 centipoise at a temperature of 177xc2x0 C. and less than about 100,000 centipoise at a temperature of 135xc2x0 C. and a heat of fusion less than about 5 joules per gram. An effective amount of a skin care composition is disposed on the cuff. The skin care composition is semi-solid or solid at 20xc2x0 C. and at least partially transferable to a wearer""s skin by contact, normal wearer motion and/or body heat.
The present invention further relates to a process for making an absorbent article to be worn by a wearer adjacent the skin wherein the process comprising the steps of:
providing a chassis wherein the chassis comprises:
an outer covering layer comprising:
a backsheet; and
a liquid pervious topsheet joined to the backsheet; and
an absorbent core positioned between the topsheet and the backsheet. A cuff is provided whereby each cuff is joined to the chassis. Each cuff has a first surface and a second surface disposed opposite the first surface. The cuff comprising a cuff member and an elastic member wherein the elastic member has opposed elastic ends and the elastic member is joined to the cuff member using an oil resistant adhesive. The oil resistant adhesive exhibits an apparent viscosity less than about 20,000 centipoise at a temperature of 177xc2x0 C. and less than about 100,000 centipoise at a temperature of 135xc2x0 C. and a heat of fusion less than about 5 joules per gram. An effective amount of a skin care composition is disposed on the cuff. The skin care composition is semi-solid or solid at 20xc2x0 C. and at least partially transferable to a wearer""s skin by contact, normal wearer motion and/or body heat.